Methods: Finite element models of T12 and L1 were constructed from computed tomography images of osteoporotic patients. Three analyses were conducted: (1) the impact of various screw diameters with DEPST, (2) a comparison of fixation strength between short DEPST (S-DEPST), which penetrates the posterolateral endplate, and conventional DEPST (C-DEPST), and (3) a comparison between conventional cancellous thread screws (CTS) and endplate screws (ETS). Pullout strength (POS) was measured in all analyses. Vertebral motion angle (VMA) of the lower instrumented vertebra (LIV) was measured in analyses (2) and (3), and the four-directional load test (4DLT) was performed in analysis (2). Results: Larger screw diameters with DEPST correlated with elevated POS. S-DEPST demonstrated significantly better fixation strength with a POS 1.46 times higher than C-DEPST and 2.5 times higher than traditional trajectories. S-DEPST also demonstrated higher fixation in all directions in 4DLT. However, no significant difference was observed in the VMA of LIV. ETS demonstrated slightly higher fixation than CTS, but the difference was not statistically significant. Conclusions Fixation strength improved with larger screw diameters in DEPST. S-DEPST provided additional fixation due to rim penetration. ETS may offer a higher fixation strength and warrants further validation.

Methods: In total, 828 patients (338 males and 490 females; mean age, 65.0 years) who underwent spinal instrumentation surgery from 2013 to 2021 in Kyorin University School of Medicine were retrospectively investigated. Patients were divided into the SSI (group I) and non-SSI (group N) groups. Patient characteristics, comorbidity, laboratory, and surgical factors were investigated. Univariate analysis was performed for each item, and multivariate logistic regression analysis was performed for items with significant differences. Results: Fifteen patients (1.85%) had SSIs. Univariate analysis revealed significant differences between groups I and N in history of steroid use, serum albumin, C-reactive protein, number of fixed vertebrae, and perioperative blood transfusion. Multivariate logistic regression analysis showed that a history of steroid use (odds ratio [OR], 5.38; 95% confidence interval [CI], 1.41–20.49; p=0.014), serum albumin (OR, 0.34; 95% CI, 0.13–0.84; p=0.020), and perioperative blood transfusion (OR, 5.85; 95% CI, 1.46–23.50; p=0.013) were independent risk factors for SSIs. Conclusions The results of this study indicate that preoperative nutritional intervention, appropriate management of anemia, and intraoperative and postoperative bleeding control may decrease the incidence of SSIs. However, this study has several limitations, including its retrospective design, analysis of a few SSI cases, and inclusion of various surgical approaches and disease types. Future studies that address these limitations are desirable.

Methods: In total, 828 patients (338 males and 490 females; mean age, 65.0 years) who underwent spinal instrumentation surgery from 2013 to 2021 in Kyorin University School of Medicine were retrospectively investigated. Patients were divided into the SSI (group I) and non-SSI (group N) groups. Patient characteristics, comorbidity, laboratory, and surgical factors were investigated. Univariate analysis was performed for each item, and multivariate logistic regression analysis was performed for items with significant differences. Results: Fifteen patients (1.85%) had SSIs. Univariate analysis revealed significant differences between groups I and N in history of steroid use, serum albumin, C-reactive protein, number of fixed vertebrae, and perioperative blood transfusion. Multivariate logistic regression analysis showed that a history of steroid use (odds ratio [OR], 5.38; 95% confidence interval [CI], 1.41–20.49; p=0.014), serum albumin (OR, 0.34; 95% CI, 0.13–0.84; p=0.020), and perioperative blood transfusion (OR, 5.85; 95% CI, 1.46–23.50; p=0.013) were independent risk factors for SSIs. Conclusions The results of this study indicate that preoperative nutritional intervention, appropriate management of anemia, and intraoperative and postoperative bleeding control may decrease the incidence of SSIs. However, this study has several limitations, including its retrospective design, analysis of a few SSI cases, and inclusion of various surgical approaches and disease types. Future studies that address these limitations are desirable.

Methods: In total, 828 patients (338 males and 490 females; mean age, 65.0 years) who underwent spinal instrumentation surgery from 2013 to 2021 in Kyorin University School of Medicine were retrospectively investigated. Patients were divided into the SSI (group I) and non-SSI (group N) groups. Patient characteristics, comorbidity, laboratory, and surgical factors were investigated. Univariate analysis was performed for each item, and multivariate logistic regression analysis was performed for items with significant differences. Results: Fifteen patients (1.85%) had SSIs. Univariate analysis revealed significant differences between groups I and N in history of steroid use, serum albumin, C-reactive protein, number of fixed vertebrae, and perioperative blood transfusion. Multivariate logistic regression analysis showed that a history of steroid use (odds ratio [OR], 5.38; 95% confidence interval [CI], 1.41–20.49; p=0.014), serum albumin (OR, 0.34; 95% CI, 0.13–0.84; p=0.020), and perioperative blood transfusion (OR, 5.85; 95% CI, 1.46–23.50; p=0.013) were independent risk factors for SSIs. Conclusions The results of this study indicate that preoperative nutritional intervention, appropriate management of anemia, and intraoperative and postoperative bleeding control may decrease the incidence of SSIs. However, this study has several limitations, including its retrospective design, analysis of a few SSI cases, and inclusion of various surgical approaches and disease types. Future studies that address these limitations are desirable.